A common diabetes drug metformin's primary effect occurs in the gut and not the bloodstream, scientists have found, reversing half a century of conventional thinking.

A common diabetes drug metformin’s primary effect occurs in the gut and not the bloodstream, scientists have found, reversing half a century of conventional thinking.

The findings could create a new metformin treatment option for the 40 per cent of patients who currently can not take this first-line drug of choice, the researchers said.

Metformin was introduced as a treatment for type 2 diabetes nearly 60 years ago and is now the recommended first-line treatment for newly diagnosed patients.

The study provides strong evidence that metformin’s primary effect occurs in the gut, not the bloodstream.

The study outlines results from phase 1 and phase 2 studies involving the investigational drug Metformin Delayed Release (Metformin DR), which is designed to target the lower bowel and limit absorption into the blood.

“Our clinical trials show that metformin works largely in the lower intestine, reversing half a century of conventional thinking,” said first author John Buse, professor of medicine, and director of the Diabetes Care Centre at the University of North Carolina School of Medicine in US.

“One of the top reasons metformin isn’t used for all people with type 2 diabetes is that patients with impaired kidneys accumulate too much drug in the blood, and this can result in life-threatening lactic acidosis,” Buse said.

“These studies provide evidence that delivering Metformin DR to the lower bowel significantly reduces the amount of metformin in the blood, while maintaining its glucose-lowering effect,” he said.

Because of this, Metformin DR may prove to be a treatment option for the four million type 2 diabetes patients in the US with impaired kidney function, researchers said.